Eh, I didn't see any mandatory eye protection rules, and I'm afraid that instant-kill headshots might lead to a few eye/face injuries, so it might be a good idea to either provide eye protection or discourage going for the head entirely.
I'd like to clarify that by definition a Bullpup is a firearm which has a magazine port rearward of the grip, not the firing mechanism. Chop off some of the longshot's front, move the grip and trigger assembly forward, call it a day.